Galapagos Now

The trail up Sierra Negra volcano, one of five that form this horseshoe-shaped island, begins in the misty highlands above town. Three weeks ago, the volcano erupted for more than a week, but it's since calmed down to a moderate smolder. A quick hike takes us through underbrush thick with guava bushes, quick-spreading invaders that are nonetheless full of tasty fruit.

Indeed, along with illegal fishing, invasive plants and animals are the most serious ecological threat to the islands. The Ecuadoran government went so far as to hire a helicopter hunting team from New Zealand to rid Isabela of hundreds of thousands of feral goats that infested the island, left by sailors and settlers. It's working: The three northernmost volcanoes were estimated to be free of goats by the end of 2005, and fewer than 50,000 are left on the entire island.

To reach the active vent on the far side of the rim, we have to hike a third of the way around the crater. At six miles across, it's the third-largest in the world. Steam rises from a dozen spots in the fresh black lava that covers half the crater floor. Our boots crunch over chunks of iridescent lava that rise and fall around the rim like glassy black sand dunes. It smells like an old campfire. On top of the final hill, we gaze into the gaping vent, feeling like we're standing over an open oven.

Puerto Villamil is peaceful after dark. The snack shop is the only place open on the town plaza, where palm trees sway. After scooping our cones, the elderly proprietor pops on a homemade DVD of the eruption. Despite the shaky camerawork, it's mesmerizing. We munch our dessert and watch plumes of lava spurt 100 feet in the air.

"I love the peace and quiet here," says Isabela resident Marita Zecchettin. "I've been here 12 years, and I'm never going to leave."

"I'm scared about what's happening to the islands," she says. "We want special people who come here for the peace and quiet, not just more tourism." In 1998, when she opened the Casa de Marita, the cozy Puerto Villamil beach hotel where we are staying, there were three other hotels in town. Now there are 11.

Tonight every hotel in town is full.

Into the Deep Blue

The next morning we take a prop plane to Puerto Baquerizo Moreno on San Cristobal Island. I hardly recognize the dusty, quiet town I visited nine years earlier. Hotels, tour companies, Internet cafes and new construction are everywhere.

This month, a 500-passenger cruise ship will dock for a night in this city of 6,000, a first for the islands. (At the moment the largest tour boat in the islands holds about 100 passengers.) Twelve such visits will be allowed every year.

I think about this as we paddle nine miles to Puerto Grande Beach on the island's western shore. Kicker Rock rises a few miles offshore, jutting skyward like a 500-foot stalagmite. It's separated from even larger, flat-topped Sleeping Lion Rock by a channel as deep and narrow as a Manhattan street.

The last day of kayaking is the most exciting. We ride the panga to Kicker Rock and snorkel in the narrow, coral-lined channel between the formations. Yellowtail surgeonfish, barracuda and Galapagos sharks swerve in the deep blue below us.

After lunch we paddle single file through a hole carved in the shoreside cliffs, barely wide enough for our strokes. The surf surges like a roller coaster and booms off the walls. The timing is as tight as the fit. Wait . . . now! Go!

Everyone makes it in one piece, whooping with relief.

Our final stop is Playa Ochoa, north of Puerto Grande, where sea lions sprawl on fine powdery sand. Newborn pups bleat like billy goats, demanding milk from their mothers.

As we ride the panga back to town, two Darwin's finches perch on the cabin roof, obviously looking for a snack. With their variously shaped beaks, the islands' finch species helped inspire the naturalist's momentous idea of distinct species arising from a common ancestor. Over time they've adapted to the food sources they've found here, developing short heavy beaks to crack hard seeds and long thin beaks to get grubs buried deep in trees.

Apparently this one has found another meal ticket, just one more example of the Enchanted Islands' ongoing evolution. After all, if there's one thing Darwin taught us, it's that life's one constant is change.

ROW International's nine 2006 departures are all full or nearly so, though the firm may be adding dates. The 11-day kayaking trips cost $2,690 or $2,890 per person, depending on how many are in the group ($2,890 or $2,990 in 2007) and include camping equipment, hotel rooms, most meals, guides and transfers. International airfare to mainland Ecuador, the flight to the Galapagos ($392 round trip), two short inter-island flights ($180 per person) and the Galapagos park entrance fee ($100 per person) are extra. Info: 800- 451-6034,http://www.rowinternational. com.

Julian Smith is the author of the guidebook "Moon Handbooks Ecuador," which includes the Galapagos Islands. He last wrote for Travel about kayaking off the coast of Kauai.